Design and performance of the 33-BM beamline at the Advanced Photon Source

摘要

The APS sector 33 bending magnet beamline was designed to provide high X-ray flux with relatively small focal spot (1 mm × 0.5 mm with ~10~(12) ph/s/100 mA flux) and energy resolution limited mostly by the intrinsic resolution of the monochromator optics, δE/E=1.5 × 10~(-4). The beamline accepts 4 mrad of the dipole radiation fan and uses a fixed offset design. A collimating mirror is followed by a double-crystal monochromator with a sagitally bent Si second crystal. A second mirror is dynamically bent to vertically focus or to collimate the beam at the experiment location. This design successfully delivers focused X-rays with an energy range from 5 to 38 keV for use in diffraction measurements of thin films, interface structures and bulk materials. The monochromator has scanning capabilities that also enable anomalous scattering techniques. Experiments that demonstrate the performance of the beamline will be described.